Field of the Invention
The present invention relates to a switching regulator which outputs a constant voltage, and more specifically to a switching regulator equipped with an overheat protection circuit which detects a temperature to stop a switching operation.
Background Art
Low power consumption has recently been progressing in an electronic device equipped with a battery. The low power consumption of the electronic device has been further strongly required to make a battery driving time longer particularly in a smart phone, a portable device, a wearable device, etc. Therefore, a reduction request for power consumption is remarkable even in a semiconductor integrated circuit built in the electronic device.
On the other hand, such safety as not to exert adverse effects such as an explosion, an electric shock, etc., on a human body is particularly required for the above electronic device directly handled by a person. For example, as a switching regulator built in a battery-driven electronic device and using a battery voltage as an input voltage, there has been known one equipped with an overheat protection circuit which stops its operation when a chip temperature in a semiconductor integrated circuit rises and reaches a temperature not less than a prescribed temperature.
[Patent Document 1] Japanese Patent Application Laid-Open No. Hei 06(1994)-244414
However, when a protection circuit for ensuring the safety is added, power for operating the protection circuit is required.